The present invention relates to a Video/audio processor system having, for example, a Video processor apparatus such as a television (TV) receiver, and an AV (audio/Video) amplifier. The invention further relates to an amplifier device and an audio delay processing method for use with the video/audio processor system.
For example, with an Video/audio terminal device of a TV conference system, when processing and playing back a Video signal and audio signal being sent, the amount of data and of the Video signal is greater than that of the audio signal, and also the processing is relatively complex, so that outputting of video is delayed with respect outputting of audio, whereby there occurs an offset between audio and video inherently required to be accurately synchronized, consequently generating non-synchronous (or, asynchronous) audio and Video (event of the unmatch between audio and Video character's mouth movements), i.e., so-called lip sync error.
To address the problem of such lip sync error, below-described Japanese Unexamined Patent Application Publication No. 07-059030 discloses a technique as briefed herebelow. According to the technique, in an apparatus for coding video signals and audio signals and produces outputs thereof, a necessary amount of delay of an audio signal from the coded state of the audio signal is set. Then, in accordance with the set amount of delay, the coded audio signal is delayed, whereby the video and audio signals are synchronized with one another and output. Then, the Video and audio signal are sent to a destination, thereby to prevent the occurrence of the lip sync error in a destination terminal device.
In recent years, configuration of so-called home theater systems has become popular. For example, the configuration of a home theater system can be configured by interconnecting a DVD (digital Versatile disc) player, an AV amplifier, and a TV receiver with a relatively large display screen.
In this case, the AV amplifier, which forms audio signals for supply to respective speakers corresponding to multiple channels, such as the 5.1 channels, supplies audio signals to a corresponding speaker, and synchronously supplies video signals to the TV receiver. In the TV receiver, the video signals from the AV amplifier are processed to form video signals for supply to a display device of, for example, an LCD (liquid crystal display), a PDP (plasma display panel), or CRT (cathode-ray tube), and the signals are supplied to the display device.
In this manner, an audio signal is processed by an AV amplifier, and a video signal is processed by a TV receiver; that is, the audio signal and the video signal are processed by different devices. As such, the time taken for the processing of the video signal in the TV receiver cannot be known in the AV amplifier. Thus, different from the case of the technique disclosed in the technique disclosed in the Japanese Unexamined Patent Application Publication No. 07-059030, the delay cannot be provided in the manner that the delay time of the audio signal is easily and automatically set.
In such a case as described above, if an AV amplifier capable of performing delay processing of an audio signal is used, a user has to manually set the amount of delay of the audio signal, and has to finely adjust the delay. However, in many cases, such setting and fine adjustment of the amount of delay of the audio signal are complex processing for an unskilled user, so that the amount of delay cannot be adjusted to satisfaction.
Of course, a case can be considered in which, to form a home theater system from the beginning, a set of a DVD player, AV amplifier, and TV receiver is purchased, and the adjustment is performed by, for example, a technical or service person stationed in an electrician store. However, it is time-consuming and burdensome to call for such a service person every time the adjustment is performed, and costs, such as service fees to be paid to the for the adjustment, can occur.
In view of the above, the present invention proposes a system, apparatus, and method capable of preventing so-called lip sync error in a system that uses different devices to process audio signals and video signals.